Operating sliding doors.



i "No-i 806,220. PATENTBD DEG.5,1905.

. P.- D. WARD.

OPERATING SLIDING DOORS.

- APPLICATION mum we. 6 1904.

I 2 sums-ann- 1.

No. 806,220. PATENTED mm, 1905.

. P. 11. WARD. OPERATING SLIDING DOORS.

' 2 SHEBTS-SHBET 2.

APPLICATION FILED AUG. 6, 1904.

UNITED STATES FRANK DIETR oH WARD, or HANWELL, ENeLANn-hss'ierioia OF ONE- HALF TO HENRY PERCY BRADFORD, or LONDON, ENGLAND.

OPERATING SLIDING DOORS.

Specification of Letters Patent.

Patented'Dec'. 5, 1905.

Application filed August 6,1904. Serial No. 219,756.-

To cZZZ whom it may concern: I

Be it known that I, FRANK DIETRICH WARD.

a subject of the King of Great Britain, residcrating Sliding Doors, of whiohthe following is a specification,

This invention has for its object to provide means whereby sliding doors can be operated by pneumatic pressure, the invention being chiefly intended for operating the sliding doors used upon railway-carriages. According to the said invention each door has arranged .in conjunction with it twosingle-act i'ng cylinders and pistons, means being provided for introducing compressed air alternately into the two cylinders.

' In carrying out the invention it is preferable to employ -two single-acting cylinders,

' which are fixed tothe upper part'of the door and in each of which is a piston carried by a rod secured to a suitable support and held rig-' idly, the pistons being arranged in such relation to one another that when one piston is at the outer end of its cylinder the other piston is at the inner end of its cylinder. For introducing air into the respective cylinders the piston-rods are advantageously made tubular and are connected with a suitable air-supply controlled by a four-way'valve or tap in such a manner that when air is being introduced into one cylinder the air from the other cylinder will be allowed to exhaust. The door is mounted upon runners'to relieve the cylinders and pistons from any'strain.

To enable the invention to be fullyunderstood, reference is made to the accompanying drawings, in which Figure 1 is an elevation of a portion of a sliding door and frame having two single-acting cylinders and pistons applied to it. Fig.

.2 is a sectional elevation, drawn to an enlarged opening to be closedby the said door, the latter, as shown, being suspended from two trolleys c 0, running upon a rail (Z.

e f are two single-acting cylinders secured to the upper part of the door 0Zfor instance, by means of brackets,.s'uch as g gand h "Z, are the pistons in the cylinders e f, respectively. h 11 are the respective rods of the said pistons, which rods are made tubular, the passages therein extending into the cylinders, as

indicated in Fig. 2. These rods Z. Z have air pipesjj connected to them and extend to a four-way valve, such as k. This valve, which is shown drawn to an enlarged-scale in F1gs.

4, 5, and 6, has in it ports Z Z in connection with the pipes j j, respectively, and other ports on 221/, through which the air is exhausted, as hereinafter described. The plug Z," of the cock is made hollow and has a pipe at communicating with it and with the compressed air supply. shown, is adapted to be moved'by a lever 0 through an angle of ninety degrees, stops 1? 10 serving to limit the movement of the plug. In the plug are formed two ports gin connection with the ports ZZ and two. channels r for connecting the ports Z we and Z m. With this arrangement when the plug is, say,'in the position shown in Fig. 7 the air entering the valve through the pipe at will pass through the corresponding port q in the plug to the port Z and thence through the pipe j to the cylinder 0, the result being that the door will be moved in the direction of the arrow, Fig. 1, while the air from the cylinderf will flow through the pipe to the port Z and thence through one of the passages r to the exhaustport m. Upon the alteration of the position of the plug of the cock through ninety degrees the reverse action would take placethatis to say, air willbe admitted through the port Z into the cylinder f and escape from the cylinder '6 through the'exhaust-port m.

Although in the foregoing. description I have represented only a single door, it will be obvious that a pair of doors or a series of single doors or pairs of doors can be controlled simultaneously by the operation of a single valve if the mechanism of all the doors 1s operated'from the same air-pipes.

By employing two cylinders,as shown in the drawings, all glands or stuffing-boxes surrounding the piston-rods are dispensed with,

The plug itself, as

and the only packing necessary is that around the pistons. This effects a considerable saving in expense and increases the durability and effectiveness of the apparatus, as will be readily seen.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. Mechanism for operating sliding doors, comprising among its members, two separate reversely-disposed cylinders, each provided with a piston and means for admitting a motive fluid in rear thereof, said pistons and cylinders being connected the one to a movable door and the other to a stationary part Whereby the use of stuffing-boxes for the pistonrods may be obviated, substantially as described.

2. The combination with a sliding door, of a pair of separate reversely-disposed cylinders FRANK DIETRIOH WARD.

Witnesses:

H. D. J AMEsoN, F. L. BAND. 

